package 蓝桥真题;

public class 相乘 {
       public static void main(String[] args) {
		      long m=1000000007;
		      for(int i=1;i<=1000000007;i++){
		    	  if(((i*2021L)%m)==999999999){
		    		  System.out.print(i);
		    		  return;
		    	  }
		      }
		      System.out.print(0);
	}
}
